Steel Charcoal Kiln by The Charcoal Burners UK – Direct Method

traditional method of charcoal making – The Direct Method

For making charcoal in indirect method , please read this article : charcoal in indirect method

Charcoal of Adam Retort

The direct method uses heat from the incomplete combustion of the organic matter, which is to become charcoal. The rate of combustion is controlled by regulating the amount of oxygen allowed into the burn and is stopped by excluding oxygen before thecharcoal itself begins to burn. This is the ages old method used by colliers to make charcoal in a pit, pile (clamp) or, more recently, in metal or masonry chambers (kilns).

Read The article below for more information about making charcoal with direct method

Portable Charcoal making Kiln 3

We make our charcoal from locally sourced wood, usually cut down by me, Chris. I chop it into pieces which are the size that experience has taught me are best for making into charcoal.

Then it gets stacked up and left to season for just over a year.

After seasoning, we can use the wood. So the first layer of timbers to go in the kiln are placed in an open cartwheel or star shape (not shown here). This allows air to enter the kiln at the base, ensuring good air flow for the first stage of the burn.

Then for each subsequent layer, the logs are placed around the circumference of the kiln, and then spiraling inwards until a fairly small hole in the middle of the stack remains.

When the kiln is about half full we put the the ‘charge’, or tinder into this central hole. This is very dry and highly combustible material, which ensures a good strong fire.

Then the process of laying the logs down in a spiral fashion continues until they show about 4″ above the top of the kiln and form a conical shape up to the centre. The lid is then hauled up into position, making certain that it sits centrally.

With the lid jammed open to allow good air flow, the kiln is now ready to be lit. The ideal time to light a burn is on a windless and settled day, because any wind at all makes it much harder to control the way the fire burns.

So to light the burn, rags are set alight and thrust into the central charge via the air inlets created by the frist ‘cartwheel’ layer. Once we hear ‘snap, crackle & pop’, there is no going back!

The burn is now under way and for the next 2 to 3 hours the focus of work is on getting the fire to spread across the centre underside of the kiln; this is why weather conditions are so important, because if the kiln does not burn evenly, the charcoal will not form correctly and then the timber is wasted.

This picture shows our two main kilns and one smaller kiln which we use for taking to shows and doing charcoal burning demonstrations with.

As the smoke pours out the fire grows steadily stronger, until the embers start to drop around the outer edge.

In this picture we can see the base of the kiln, which is slightly raised off the ground, giving us a view of the glowing interior, and this is where we can see the embers beginning to drop down.

The fire comes round, and smoke continues to billow forth in a huge plume. At this stage when we know we have a good strong evenly-burning kiln, it is time to begin ro reduce the amount of oxygen getting into the kiln, this will slow down the burning process and if we get it right, should make us some charcoal!

So to do this sand is shovelled around the bottom of the kiln to close up the gap at the base, we do this gradually until only the eight steel shoes are left open.

The burn is still very fierce, so next we let the lid down fully. There is such phenominal heat inside the kiln, that flames leap from any gaps there are, feeding on the oxygen.

Steel charcoal kiln

Next we need to seal up the lid properly with sand. As you can see from this picture this is a very hot and dangerous job! Large flames are still dancing out from the shoes at the base of the kiln, so great care must be taken.

Heavy metal chimneys are now placed into 4 of the shoes to create exhaust flues. The other 4 shoes become air inlets.

In the background here, to the left of the kiln, you can see my grader. This is a simple piece of equipment which the resulting charcoal is shovelled into, and it divides out the tiny pieces which are too small to be bagged up, and any bits which are too large don’t get through either.

For the next 14 to 20 hours we monitor progress, as it’s important to ensure the kiln stays sealed. We add sand to any gaps that appear as the burn chugs on into the night.

The smoke from the chimneys gradually grows thinner; we are looking for a change in the colour of the smoke from gray to blue, when this happens we know the burn is complete.

Eventually the chimneys will be removed and all 8 shoes are blocked off with sand, thus sealing the kiln completely.

The kiln is left for at least 24 hours to cool down, and during this time we must still keep checking that the sand keeps it sealed. Once cooled and safe enough to work with again, the lid can be lifted.

The moment of truth…. Now we discover what we have made!

We can now begin shovelling the charcoal out through the grader, which removes most of the ash and fines – these are the bits which are too small to be sold as charcoal, you can see them collecting underneath the grader.

Finally the charcoal is bagged up and ready to be sold!

If you are in the UK and wanna buy some of charcoal from the owner of this post , please visit charcoalburners.co.uk . thanks!

Check nextpage for the charcoal making direct method process in videos:

Read this article for making charcoal in indirect method

There are serveral ways to make a retort – kilns to make charcoal in small scale. At this blog, i’ll show you alot of them